Contraindications Flashcards
Adrenaline
✅No contraindications for cardiac arrest or anaphylaxis
❗️Caution when using for vasoconstriction in those with heart failure and at end artery sites e.g fingers and toes
💊Interactions: may cause widespread vasoconstriction in people on beta blockers
Glucocorticoids (systemic)
❗️caution in people with infection
❗️caution in children
💊 Cytochrome p450 inducers (⬇️ efficacy)
💊 NSAIDs - increased risk of peptic ulcers and GI bleeding
💊 Beta2 agonists/Diuretics/Theophylline - increased risk of hypokalaemia
Thiazide Like Diuretics
❌ Hypokalaemia
❗️Hyponatraemia
❗️Gout
Statins
❗️Hepatic impairment
❗️Renal impairment (lower dose)
❌ Pregnancy
❌ Breastfeeding
💊 Cytochrome p450 inducers - reduce metabolism of statins therefore more side effects. May need to reduce statin dose or temporarily withhold.
💊 Amlopidine
Clopidogrel
❌ active bleeding
❗️stop 7 days before elective surgery
❗️hepatic and renal impairment
💊is a pro-drug therefore cytochrome p450 inhibitors reduce efficacy
💊use lansoprozole over omeprazole for gastric protection
💊increased risk of bleeding with other antiplatelets, anticoagulants or NSAIDs
Antihistamines
❗️severe liver disease as sedating antihistamines may precipitate hepatic encephalopathy
5a-reductase
Finasteride
❌ Pregnant
Alpha blockers
Doxazosin, tamsulosin, alfuzosin
⁉️Postural hypotension- avoid
Acetylcholinesterase inhibitors
Donepezil, Rivastigmine
❗️Asthma ❗️COPD ❗️Risk of peptic ulcers ❌ heart block ❌ sick sinus syndrome ❗️may worsen tremor in Parkinson’s
💊NSAIDs and corticosteroids may increase risk of peptic ulcer
💊 Antipsychotics increase risk of neuroleptic malignant syndrome
💊 B-blockers may contribute to heart block/bradycardia
B-blockers
Propanolol, bisoprolol, atenolol, metoprolol, carvedilol
❌Asthma as can cause bronchspasm
❗️heart failure start slow as can initially impair cardiac function ❗️Haemodynamic instability - avoid
❌ Heart block
❗️Hepatic Failure - reduce dose
💊❌Non-hydropyridine calcium channel blockers (e.g. verapamil, diltiazem) as can cause 💔
Acetylcysteine
None - even in hx of anaphylactoid rxn
Activated charcoal
⚠️ Persistent vomiting (risk of aspiration)
⚠️ Reduced gut motility (risk of obstruction)
Adenosine
Avoid in those who will not tolerate bradycardic effects:
❌Hypotension
❌Coronary ischaemia
❌decompensated heart failure
Avoid in those susceptible to bronchospasm
❌asthma
⚠️COPD
⚠️ Heart transplant
💊 Dipyridamole (an antiplatelet) blocks cellular uptake of adenosine which prolongs its effect therefore the dose should be halved.
💊Theophylline and aminophylline are competitive antagonists of adenosine receptors therefore reduce its effect and patients may require higher doses
Aldosterone antagonists
spironolactone, eplerenone
❌Severe renal impairments
❌Hyperkalaemia
❌Addison’s disease (who are aldosterone deficient)
Can cross placenta so ⚠️ in pregnancy
💊 Combo with other potassium elevating drugs e.g. ACE-i and ARBs increases risk of hyperkalaemia therefore monitor closely
💊❌ Potassium supplements
Alginates and antacids
Gaviscon, Peptac
⚠️Paediatric alginates should not be given with thickened milk preparations as can cause bloating and discomfort
⚠️Sodium and potassium containing preparations should be used with caution in patients with fluid overload or hyperkalaemia e.g. renal failure
⚠️Some preps contain glucose which can worsen hyperglycaemia in people with DM
Allopurinol
❌Acute attack of gout (if not already started)
❌Recurrent skin rash
❌Severe hypersensitivity to allopurinol
It is metabolised in liver and excreted by kidney therefore reduce dose in
⚠️Renal impairment
⚠️Hepatic impairment
💊Azathioprine active metabolite is metabolised by xanthine oxidase therefore increased toxicity risk if both given
💊Co-px with ACE-i or thiazides increases risk of hypersensitivity reactions
Aminoglycosides
gentamycin, amikacin, neomycin
Renal excretion - impt to monitor plasma drug concentrations to prevent renal, cochlear and vestibular damage, particularly in ⚠️neonates, ⚠️elderly patients and those with ⚠️renal impairment.
⚠️ Myasthenia gravis as can impair neuromuscular transmission
💊Loop diuretics or vancomycin increase risk of ototoxicity
💊Ciclosporin, platinum chemo, cephalosporins or vancomycin increase risk of nephrotoxicity
Aminosalicylates
mesalazine, sulfasalazine
❌ Aspirin hypersensitivity
💊Mesalazine tablets with pH-sensitive coating may interact with drugs e.g. PPI’s or lactulose that alter gut pH
Amiodarone
Avoid in patients with
⚠️severe hypotension
⚠️heart block
⚠️active thyroid disease
💊Loads of stuff but notable = digoxin, ditilazem, verapamil which get increased plasma concn that increases risk of bradycardia, AV block and heart failure. Halve the doses of these if start amidarone.
ACE-i
ramipril, lisinopril, perindopril
❌Renal artery stenosis
❌Acute kidney injury
⚠️pregnant or breastfeeding
⚠️CKD - use lower doses
💊Avoid potassium-elevating drugs
💊Other diuretics –> profound first-dose hypotension
💊NSAIDs increase risk of nephrotoxicity
ARBs
losartan, candesartan, irbesartan
❌Renal artery stenosis
❌Acute kidney injury
⚠️pregnant or breastfeeding
⚠️CKD - use lower doses
💊Avoid potassium-elevating drugs
💊Other diuretics –> profound first-dose hypotension
💊NSAIDs increase risk of nephrotoxicity
Antidepressants - SSRIs
citalopram, sertiriline, fluoxetine, escitalopram
⚠️epilepsy
⚠️peptic ulcer disease
⚠️young people (increased risk of self harm and suicide)
Metabolised by liver therefore ⚠️ hepatic impairment
💊❌ Monoamine oxidase inhibitors and ⚠️other serotergic drugs as may precipitate serotonin syndrome
💊 Consider gastroprotection with aspirin or NSAIDs as increased risk of bleeding
💊 Caution with anticoagulants as increased bleeding risk
💊Do not combine with drugs that prolong the QT interval e.g. antipsychotics
Antidepressants - tricyclics and rltd drugs
Amtriptyline, lofepramine
⚠️epilepsy ⚠️elderly ⚠️cardiovascular disease Antimuscarinic effects may worsen condition in people with: ⚠️prostatic hypertrophy ⚠️glaucoma ⚠️constipation
💊❌ Monoamine oxidase inhibitors as both increase 5-HT and NA levels at the synapse and together they can precipitate hypertension and hyperthermia or serotonin syndrome.
💊Tricyclics can augment antimuscarinic, sedative or hypotensive adverse effects of other drugs
Antidepressants, venlafaxine and mirtazapine
⚠️elderly
Consider dose reduction in people with ⚠️hepatic or ⚠️renal impairment
Venlafaxine should be used with caution in pts with ⚠️arrhythmias (e.g. due to ischaemic heart disease)
💊Other depressants in combo can increase risk of adverse effects including serotonin syndrome
Antiemetics - D2 receptor antagnoists
metoclopramide, domperidone
To reduce risk of extrapyramidal effects metoclopramide should be prescribed for 5d max. Avoid in:
❌neonates ⚠️children ⚠️ young adults
Domperidone is contraindicated in patients with:
❌cardiac conduction abnormalities ⚠️severe hepatic impairment
Avoid both drugs in:
⚠️intestinal obstruction ❌perforation
Metoclopramide should be avoided in ⚠️Parkinson’s disease but domperidone okay
💊antipsychotics (increases risk of extrapyramidal side effects)
💊❌dopaminergic agents for Parkinson’s disease as it will antagonise their effects
💊❌drugs that prolong QT interval
💊❌drugs that inhibit cytochrome P450 inhibitors
Antiemetics - H1 receptor antagonists
cyclizine, cinnarizine, promethazine
Due to sedating effect avoid in pts at risk of:
⚠️hepatic encephalopathy
⚠️prostatic enlargement (as susceptible to anticholinergic effects)
💊increased sedation effects e.g. benzos, opioids
💊increased anticholinergic effects e.g. ipratropium or tiotropium
Antiemetics - 5-HT3 receptor antagonists
ondansetron, granisetron
Avoid in patients with ⚠️ prolonged QT interval
💊Avoid drugs that prolong the QT interval (e.g. antipsychotics, quinine and SSRIs)
Antifungal drugs
nystatin, clotrimazole, fluconazole
Topical - no contraindications
Fluconazole - ⚠️liver disease, ⚠️reduce dose in renal impairment, ❌ pregnancy
💊fluconazole increases plasma concn of drugs metabolised by CYP enzymes (e.g. carbamazepine,, phenytoin, warfarin, dizepam, simvastatin and sulphonylureas)
💊reduce antiplatelet action of clopidogrel
💊increases risk of arrhythmias if with drugs that prolong QT interval (amiodarone, antipyschotics, quinine, quinolone, macrolides and SSRIs)
Antihistamines - H1 receptor antagonists
cetirizine, loratidine, fexofenadine, chlorphenamine
Sedating antihistamines (e.g. chlorphenamine) should be avoided in ⚠️severe liver disease as may precipitate hepatic encephalopathy
Antimotility drugs
loperamide, codeine phosphate
⚠️ Acute ulcerative colitis - as reduced peristalsis may increase risk of megacolon and perforation
⚠️C diff colitis possibility
⚠️acute bloody diarrhoea as may signify bacterial infection (risk of haemolytic-uraemic syndrome from E. coli)
Antimuscarinics - bronchodilators
ipratropium, tiatropium, aclidinium, glycopyrronium
⚠️ Angle-closure glaucoma
⚠️ arrhythmias
⚠️ urinary retention
Antimuscarinics - cardiovascular and GI uses
atropine, hyoscine butylbromide, glycopyrronium
⚠️ Angle-closure glaucoma
⚠️ arrhythmias (unless being used for bradycardia)
💊more pronounced when used with other antimuscarinics e.g. tricyclic antidepressants
Antimuscarinics - GU uses
oxybutynin, tolterodine, solifenacin
❌ UTI - therefore do urinalysis ⚠️ elderly as neurological side-effects can be problematic ⚠️dementia ⚠️angle-closure glaucoma ⚠️arrhythmias ⚠️urinary retention risk
💊more pronounced when used with other antimuscarinics e.g. tricyclic antidepressants
Antipsychotics, first generation
haliperidol, chlorpromazine, prochlorperazine
⚠️ elderly - sensitive so use lower dose
⚠️ dementia - increase risk of death and stroke
⚠️ Parkinson’s disease - EPSE
💊 extensive list, careful with drugs that prolong the QT interval
Antipsychotics - second generation
olanzapine, clozapine, risperidone
⚠️ cardiovascular disease
Clozapine:
❌ Severe heart disease
❌ Neutropenia
💊 Sedation may be more pronounced used with other sedating drugs
💊 Dopamine-blocking anti-emetics
💊 drugs that prolong the QT interval (amiodarone, quinine, macrolides, SSRIs)
Antiviral drugs
aciclovir
⚠️ pregnant and ⚠️ breastfeeding (as crosses the placenta and expressed in breast milk) but often benefits outweigh risks
⚠️ severe renal impairment - as excreted by kidneys therefore reduce dose and frequency
Antiplatelets - ADP-receptor antagonists
clopidogrel, ticagrelor, prasugrel
❌ active bleeding (stop 7 days before surgery)
⚠️ renal and hepatic impairment - esp where increased bleeding risk
💊CYP inhibitors (as clopidogrel is pro-drug metabolised by CYP enzymes, e.g. omeprazole [use lansoprazole instead], erythromycin, antifungals, SSRIs
💊 ticagrelor interacts with CYP inhibitors and inducers
Increased bleeding risk with:
💊antiplatelet drugs
💊anticoagulants
💊NSAIDs
Antiplatelets - aspirin
❌ children under 16
❌aspirin hypersensitivity
❌3rd trimester pregnancy (may prematurely close ductus arteriosus)
⚠️ peptic ulceration (prescribe gastroprotection)
⚠️gout
💊caution with other antiplatelets and anticoagulants
Azathioprine
Do TMPT phenotyping first
❌absent TMPT and careful with reduced TMPT
⚠️reduce dose in liver/renal impairment
⚠️pregnancy - teratogenic in animal studies
💊other immunosuppressants as increased risk of infection
💊xanthine oxidase inhibitors - allopurinol
💊myelosupppressive drugs as increase risk of leukopenia e.g. trimethoprim
💊warfarin dose may need adjusting
β-blockers
bisoprolol, atenolol, propanolol, metoprolol, carvediol
❌asthma - as can cause bronchospasm (okay in COPD but use more selective bisoprolol, metoprolol)
❌heart block
⚠️heart failure - start low dose as can impair cardiac fxn
⚠️haemodynamic instability
⚠️hepatic failure
💊non-dihydropyridine calcium channel blockers (verapamil, diltiazem) as can cause heart failure, bradycardia and even asystole
β2-agonists
Salbutamol, terbutaline, salmeterol, formoterol, indacaterol
❗️care with patients with CVD as tachycardia can provoke angina/arrhythmias
💊 β-blockers will reduce effects
💊 Use with theophylline and steroids can precipitate hypokalaemia
Benzodiazepines
diazepam, temazepam, lorazepam, chlordiazepoxide, midazolam
⚠️ elderly need a lower dose
⚠️ avoid in resp impairment
⚠️avoid in neuromuscular disease e.g. myaesthenia gravis
⚠️avoid in liver failure as can precipitate hepatic encephalopathy (but if essential use lorazepam)
💊Concurrent use with CYP inhibitors may increase their effects (e.g. amiodarone, diltiazem, macrolides, fluconazole)
Bisphosphonates
alendronic acid, zoledronic acid, disodium pamidronate
❌ Severe renal impairment (renally excreted)
❌ hypocalcaemia
❌ active upper GI disorder
⚠️ smokers and patients with dental disease as risk of jaw osteonecrosis
Calcium and vitamin D
calcium carbonate, calcium gluconate, colecalciferol, alfacalcidol
❌ hypercalcaemia
⚠️💊Oral calcium reduces the absorption of many drugs including bisphosphonates, tetracyclines, levothyroxine
❌💊Do not deliver IV with sodium bicarbonate as -> precipitation
Calcium channel blockers
nifedipine, amlodipine, verapamil, diltiazem
V&D:
⚠️poor left ventricular function
⚠️AV nodal conduction delay (can provoke complete heart block)
A&N:
❌Unstable angina as vasodilatation -> reflex tachycardia which increases myocardial oxygen damage
❌ Severe aortic stenosis
❌💊 β-blockers with V&D as both are negatively inotropic and chronotropic
Carbamazepine
⚠️ pregnancy (TAKE FOLATE) ❌ antiepileptic hypersensitivity syndrome ⚠️ hepatic disease ⚠️ renal disease ⚠️ cardiac disease
💊 Carbamazepine is a CYP enzyme inducer therefore reduces efficacy or other drugs metabolised by CYP (e.g. warfarin, oestrogens, progestogens)
💊 Carbamazepine is also metabolised by CYP enzymes so affected by CYP inhibitors (e.g. macrolides)
💊other antepileptic drugs
💊drugs that lower the seizure threshold (e.g. antipsychotics, tramadol)
Cephalosporins and Carbapenems
cefalexin, cefotaxime, meropenem, ertapenem
⚠️Risk of C. diff infection
❌allergy to penicillin, ceph or carbapenem (anaphylactic reaction
⚠️epilepsy
⚠️renal impairment have to reduce dose
💊 can enhance effects of warfarin as gut flora that synth vit K are killed off
💊reduce efficacy of valproate
Chloramphenicol
❌ hypersensitivity ❌bone marrow disorders (personal or family hx) ❌pregnancy 3rd trimester (systemic) ❌breastfeeding ❌children <2 years ⚠️dose adjustment in hepatic impairment
Corticosteroids (glucocorticoids), inhaled
beclometasone, budesonide, fluticasone
⚠️ COPD patients with hx of pneumonia
⚠️children - growth suppression
Corticosteroids (glucocorticoids), topical
hydrocortisone, betamethasone
⚠️infection present
⚠️facial lesions
Digoxin
❌2nd degree heart block ❌intermittent complete heart block ventricular arrhythmias ⚠️reduce dose in renal failure ⚠️hypokalaemia/magnesaemia and hypercalcaemia increase toxicity (K+ competes with digoxin for Na+/K+ ATPase pump)
💊 Loop and thiazide diuretics can ppt hypokalaemia
💊Amiodarone, CCBs, spironolactone and quinine can increase plasma concn of digoxin therefore increase toxicity
Dipeptidylpeptidase-4 inhibitors
sitagliptin, linagliptin, saxagliptin
❌hypersensitivity ❌Type 1 diabetes ❌ Ketoacidosis ❌ Pregnancy ❌ Breastfeeding ⚠️elderly ⚠️hx of pancreatitis ⚠️renal-impairment
💊 risk of hypoglycaemia with other antidiabetic drugs (e.g. sulfonylureas and insulin)
💊β-blockers may mask hypoglycaemic sx
💊efficaacy reduced by drugs that increase blood glucose (prednisolone, thiazide loop diuretics)
Direct oral anticoagulants
apixaban dabigatran, edoxaban, rivaroxaban
❌ active bleeding ❌ risk of major bleeding ❌pregnancy ❌breastfeeding ⚠️ hepatic or renal disease (excreted by multiple routes)
💊other antithrombotic agents (e.g. heparin, antiplatelets, NSAIDs)
💊anticoagulant effect ↑ by macrolides, protease inhibitors and fluconazole
💊anticoagulant effect ↓ by rifampicin and phenytoin
